Middleware in Node.js, specifically in the context of Express.js, refers to a function that has access to the request and response objects of your application and is executed before the user-defined handler is invoked
. Middleware functions are often used in the context of Express.js framework and are a fundamental concept for building web applications
. Key aspects of middleware in Node.js include:
- Function : Middleware is a function that is executed during the request and response cycle of Node.js, providing access to the request and response objects
- Access : Middleware functions have access to the request object (req), the response object (res), and the next function in the application's request-response cycle
- Task : Middleware functions can perform various tasks, such as logging, setting headers, or modifying the request body
- Chain : Middleware functions are executed in the order they are added to the application or router, and they can modify the request and response or pass control to the next middleware function
Middleware is essential for building applications more effectively, as it helps developers track and prevent users from performing specific actions, and it acts as a connection between data, applications, and users
. It is commonly used in applications to handle common functions, such as authentication, authorization, and error handling
